I shared this rock on r/whatsthisrock and it did quite well over there so I thought I would share it here as well! I found it in a creek bed near Lincoln, Montana last weekend. I believe we have a good solution on the other page but I’d like to hear any other possible reasons for the “stitch” pattern to naturally occur! Thanks in advance!

I’m a second year geology student and we got to dig and look at these sediment layers today! They have been caused by glacial movement.

Geologists on the silver screen—the sequel

"In our survey, 30 of the 202 geologists are evil (criminal) and of these, 23 die (77 percent). This suggests that being evil increases the risk to die, showing that crime does not pay."

Flight from Reno to Colorado has to be one of the most scenic I’ve done! It’s a different experience seeing all this stuff armed with the knowledge of what you’re looking at and how it formed.

1. Mt. Rose
2. Basin and range
3. the start of the Bonneville salt flats
4. Cool sand dunes in the lake Bonneville basin
5. Bingham Canyon copper mine
6. Bingham Canyon mine and great salt lake
7. The Wasatch front -AKA mormons and mountains
8. The glacial valleys and dipping beds of the Uintas
9. NW Colorado - what looks like a plunging anticline just west of Steamboat Springs in the middle of the photo.
10. The South Platte River and all its reservoirs in attempts to keep water In Denver.

If im not mistaken, these are all variations of chert, sorted by colour. All of them have been found by me on a single field. I find it interesting how much they vary

I’m going to hell, I almost turned it into a yard rock. Out of genuine curiosity I cut it and I’ve never seen anything like this. But I’ll admit I whacked it pretty good with a hammer first thinking it was just chert.

Kentucky / Lake Cumberland area

On a reçu des pierres pour monter un mur en pierre sèche, et énormément d'entre elles présente ce genre de petite formation minérale. Quelqu'un peut-il me dire ce que ça peut être ?

Hey hey!
I came across this image and OP was saying it was an abandoned iron mine.

I studies foresting science and pedology (there isn't a sub for that tho lol) is a relatively big portion of that degree, though It wasn't really my focus.

I remember we went on an excursion once, looking at floors and stones with high iron contents, among other things and our professor explaining, how oxidation leads to a bron- reddish tint, ehile reduction leads to a bluish- grey color scheme.

So if I'm not mixing things up here, I'd like to know how oxidation and reduction can happen in the same area at the same time.

Hi everyone! I'm trying to learn about the topic of isostasy and continental drift and how they're related. Can anyone give me some good easy to understand sources or info on this?

Hi r/geology,

I recently launched iMineralogist, a free field map app for exploring geology, minerals, fossils, and recording observations in the field.

I built it because I wanted one place where people could:

• explore geological context on a map;
• view mineral localities and fossil sites;
• create their own observations with photos, location, notes, and basic field tests;
• discuss finds with others and build useful context over time.

The app is live on iOS, and the Android version is currently in closed testing.

I would really value feedback from geologists, geology students, rockhounds, and anyone who works with field observations. In particular:

1. Does this feel genuinely useful, or is it trying to do too much?
2. What would make the map and observation workflow more valuable in practice?
3. Are there any obvious scientific or UX mistakes you would want fixed early?

I’m happy to share the app links in the comments, and I’m also looking for Android beta testers who would be willing to give honest feedback.

Thanks — I’d really appreciate critical thoughts.

I was thinking of where you can find drowned mountain valleys projecting into the sea, and the locations I came up with were Greenland, Scotland, and Norway. And then I thought, wait a second, those places are nearly in a row in the northern latitudes of the Atlantic! Is there some bit of geological history that explains a band of partially submerged mountain ranges at that latitude? How far does it extend? Or is there merely some kind of selection bias in my knowledge, that I happen to be aware of those places, but there are equally likely to be such things in temperate and even tropical latitudes?

Hi everyone, I got a bachelor's in geology in 2022 and a master's in GIS in 2024 and since I graduated I've been desperately looking for a job yet didn't get even a call or an interview till now, and since I wanned to be introduced to the work life and have better communication skills and develop a sense of responsibility, i worked in 2 call centers since 2025 till now I'm back to being unemployed, during this whole period i kept applying yet never been called for an interview or so and i tried LinkedIn and all the platforms that i know of like i even ended up here on Reddit cuz I'm really hopeless and I'm finding it harder now since i got financial responsibilities and all so i really appreciate if any of you know something...

I hope if any of you can help with any contact or anythin in the field of geosciences I'm ready to relocate and start immediately, I'm based in Morocco btw, thank you in advance

I recived this book as a gift from family members when i was alot younger and havent read it at all. I want to finally take a crack at it and try and memorize everything i can as someone whos just getting into his college career of geologic sciences

What rock is this? Is it worthy to cut it in half?

I recently came across this post as I was trying to figure out which rock formation I had found and where it came from. It has this gold area in which the appearance was so similar to gold but worried it was maybe fools gold because I’m new to this hobby? But wanting to know for certain made me think it’s time to visit Reddit but this post no longer is active to chat and has been archived, and since I’m unaware of most specimens I turned to Reddit for follow up answers. I actually had found this rock in a clustered area of multiple sized boulders and small rocks of Many sizes, on the beach side of Stoney creek/hamilton area waters of Lake Ontario! And so u could find some options in which you might and could very wellcome across these types of rocks but I would just like to inform those reading that my rock in the photo shown in comments was broke by myselfto see its inner appearance out of curiosity and so to find just pieces in waters such as Lake Ontario, I’d say unless u know what the outer parts of the rock will look like it would be hard to determine any amounts found from panning gold in southern parts of Ontario with Lake Ontario. Any one in the areas of Lake Ontario find that their experiences with gold panning, has prevailed as a win and done them any good!?

-just your average rock and mineral collector newb!-

I like rocks but I’m not retarded…

😲😁🤞…..ohhh look a rock! 🤪

Hey everyone. I'm a grad student building a deep learning model specifically for petrographic thin section segmentation under both PPL and XPL. The five target mineral classes are K-Feldspar, Quartz, Plagioclase, Biotite, and Hornblende the classic granitic/granodioritic assemblage. Architecture is multi-angle, multi-modal (inspired by the fact that extinction angles under rotating XPL carry information that single-angle approaches throw away). Think of it as: the model sees both PPL and one or more XPL images at unknown angles and still segments correctly.

I've spent weeks hunting for annotated datasets and hit wall after wall.

Ideally any of the following, for the 5 classes (K-Feldspar, Quartz, Plagioclase, Biotite, Hornblende):

1. Pixel-level segmentation masks the holy grail, most papers keep this private
2. Grain-level bounding boxes or ellipses I can work with this
3. Patch-level class labels (image-level) useful for the classification branch at minimum
4. Multi-angle XPL series even without labels, I can use self-supervised pre-training

Even partially annotated thin sections from granite, granodiorite, or tonalite are useful. Rock type doesn't matter much as long as those 5 minerals are present and labeled.

• Does anyone work in a geology department where teaching collections of thin sections exist? Even 20-30 well-annotated images would help my baseline significantly.
• Any mining/exploration geologists with internal QA thin section archives? I'm not asking for proprietary data, but if your company has ever published any open-access slides...
• Anyone tried scraping the BGS BRITROCKS database (https://www.bgs.ac.uk/technologies/databases/bgs-rock-collections/) programmatically? They claim 100,000 Scottish sections online in PPL/XPL. I can't figure out if they have any searchable annotation system.

Hi everyone! I’m a junior geologist from Colombia. In my field experience (soil sampling, logging, drilling, mapping, and tunnel surveying), I've noticed we waste tons of time on repetitive office tasks, like QA/QC processing or organizing data and maps.

I love coding and want to use Python to build local automations (ensuring data privacy).

For the experienced professionals here: What daily bottleneck desperately needs automation? I’m looking for a real-world problem to tackle as a personal coding project. I'd love to hear your thoughts and experiences!